SpringerLink
Log in

Thermally cross-linkable hole-transport materials enable solution-processed blue OLED with LT95 over 150 h

基于热交联空穴传输材料的溶液法蓝光OLED器件LT95寿命超过150小时

  • Articles
  • Published:
Science China Materials Aims and scope Submit manuscript

Abstract

The solution-processed method for organic light-emitting diodes (OLEDs) offers the benefits of cost-effectiveness and enhanced material utilization. In the multilayer architecture of solution-processed OLEDs (SOLEDs), the role of hole-transport materials (HTMs) is pivotal for cascade hole injection. However, commercial HTMs such as poly-(9,9-dioctylfluorene-alt-N-(4-sec-butylphenyl)-diphenylamine) (TFB) are hampered by incompatible energy levels and redissolution with overlayer solvent, prompting the exploration of cross-linkable HTMs (X-HTMs) for better performance. In this study, we have developed two novel small-molecule X-HTMs, N1,N1′-((perfluoropropane-2,2-diyl)bis(4,1-phenylene)) bis(N4,N4-diphenyl-N1-(4-vinylphenyl)benzene-1,4-diamine) (FTPA-V) and N,N′-((perfluoropropane-2,2-diyl) bis-(4,1-phenylene))bis(9-phenyl-N-(4-vinylphenyl)-9H-carbazol-3-amine) (FPCz-V), which incorporate thermally cross-linkable vinyl groups and electron-rich trifluoromethyl units. The X-HTMs enhance interfacial contact through superior film formation and solvent resistance, along with optimal energy levels. The application of X-HTMs significantly enhances the efficiencies and longevities of blue, green, and red SOLEDs. Specially, blue SOLED incorporating FPCz-V exhibits unprecedented lifetime (LT95) extending to over 150 h, setting a new record for blue SOLEDs. The electrochemistry stability, high bond dissociation energy, and triplet energy levels of X-HTMs can effectively minimize exciton annihilation and prolong the lifetime. These findings underscore the potential of X-HTM optimization to propel the development of stable solution-processed luminescent technologies.

摘要

溶液法在有机发光二极管(OLED)的制备工艺中具有成本低和材 料利用率高的优势. 在溶液加工有机发光二极管(SOLED)的多层架构 中, 空穴传输层所用材料(HTM)对于级联空穴注入至关重要. 然而, 常 用的商业HTM材料TFB由于能级不匹配和上层溶剂再溶解问题而使器 件性能受限, 因此需要可交联的HTM (X-HTM)以获得更好的器件性 能. 在本研究中, 我们设计合成了两种新型小分子X-HTMs, FTPA-V和 FPCz-V, 这两种材料中均引入了热交联的乙烯基团和吸电性三氟甲基 基团. 所合成的X-HTMs具有优异的膜形貌和溶剂抗性, 优化了界面接 触. 使用X-HTMs显著提高了蓝绿红光SOLEDs的效率和寿命. 特别是采 用FPCz-V的蓝光SOLED显示出超过150小时的寿命(LT95), 是蓝光 SOLED寿命的新记录. X-HTMs的电化学稳定性、高键解能和高三线 态能级能有效地减少激子湮灭并延长寿命. 这些发现体现了交联HTM 材料的潜力, 推动了稳定的溶液加工发光技术的发展.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

References

  1. Tang CW, VanSlyke SA. Organic electroluminescent diodes. Appl Phys Lett, 1987, 51: 913–915

    Article  CAS  Google Scholar 

  2. Hong G, Gan X, Leonhardt C, et al. A brief history of OLEDs—Emitter development and industry milestones. Adv Mater, 2021, 33: 2005630

    Article  CAS  Google Scholar 

  3. Singh M, Haverinen HM, Dhagat P, et al. Inkjet printing—Process and its applications. Adv Mater, 2010, 22: 673–685

    Article  CAS  PubMed  Google Scholar 

  4. Chiba T, Pu YJ, Kido J. Solution-processable electron injection materials for organic light-emitting devices. J Mater Chem C, 2015, 3: 11567–11576

    Article  CAS  Google Scholar 

  5. Huang T, Jiang W, Duan L. Recent progress in solution processable TADF materials for organic light-emitting diodes. J Mater Chem C, 2018, 6: 5577–5596

    Article  CAS  Google Scholar 

  6. Woo JY, Park MH, Jeong SH, et al. Advances in solution-processed OLEDs and their prospects for use in displays. Adv Mater, 2023, 35: 2207454

    Article  CAS  Google Scholar 

  7. Zeng XY, Tang YQ, Cai XY, et al. Solution-processed OLEDs for printing displays. Mater Chem Front, 2023, 7: 1166–1196

    Article  CAS  Google Scholar 

  8. To WP, Zhou D, Tong GSM, et al. Highly luminescent pincer gold(III) aryl emitters: Thermally activated delayed fluorescence and solution-processed OLEDs. Angew Chem Int Ed, 2017, 56: 14036–14041

    Article  CAS  Google Scholar 

  9. Li B, Yang Z, Gong W, et al. Intramolecular through-space charge transfer based TADF-active multifunctional emitters for high efficiency solution-processed OLED. Adv Opt Mater, 2021, 9: 2100180

    Article  CAS  Google Scholar 

  10. Duan L, Hou L, Lee TW, et al. Solution processable small molecules for organic light-emitting diodes. J Mater Chem, 2010, 20: 6392–6407

    Article  CAS  Google Scholar 

  11. Yook KS, Lee JY. Small molecule host materials for solution processed phosphorescent organic light-emitting diodes. Adv Mater, 2014, 26: 4218–4233

    Article  CAS  PubMed  Google Scholar 

  12. Ohisa S, Pu YJ, Yamada NL, et al. Influence of solution- and thermal-annealing processes on the sub-nanometer-ordered organic–organic interface structure of organic light-emitting devices. Nanoscale, 2017, 9: 25–30

    Article  CAS  PubMed  Google Scholar 

  13. Nagamura N, Sasabe H, Sato H, et al. A multifunctional hole-transporter for high-performance TADF OLEDs and clarification of factors governing the transport property by multiscale simulation. J Mater Chem C, 2022, 10: 8694–8701

    Article  CAS  Google Scholar 

  14. Je H, Cho S, Kwon NY, et al. Customized orthogonal solvent system with various hole-transporting polymers for highly reproducible solution-processable organic light-emitting diodes. ACS Appl Mater Interfaces, 2022, 14: 35969–35977

    Article  CAS  PubMed  Google Scholar 

  15. Kumar K, Kesavan KK, Thakur D, et al. Functional pyrene-pyridine-integrated hole-transporting materials for solution-processed OLEDs with reduced efficiency roll-off. ACS Omega, 2021, 6: 10515–10526

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Je H, Cho MJ, Kwon NY, et al. Universal polymeric hole transporting material for solution-processable green and blue thermally activated delayed fluorescence OLEDs. ACS Appl Mater Interfaces, 2023, 15: 9792–9799

    Article  CAS  Google Scholar 

  17. Niu YH, Liu MS, Ka JW, et al. Crosslinkable hole-transport layer on conducting polymer for high-efficiency white polymer light-emitting diodes. Adv Mater, 2007, 19: 300–304

    Article  CAS  Google Scholar 

  18. Xu Z, Tang BZ, Wang Y, et al. Recent advances in high performance blue organic light-emitting diodes based on fluorescence emitters. J Mater Chem C, 2020, 8: 2614–2642

    Article  CAS  Google Scholar 

  19. **e FM, Li HZ, Zhang K, et al. Rational multidimensional shielded multiple resonance emitter suppresses concentration quenching and spectral broadening for solution-processed organic light-emitting diodes. ACS Appl Mater Interfaces, 2023, 15: 39669–39676

    Article  CAS  PubMed  Google Scholar 

  20. **e FM, An ZD, **e M, et al. tert-Butyl substituted hetero-donor TADF compounds for efficient solution-processed non-doped blue OLEDs. J Mater Chem C, 2020, 8: 5769–5776

    Article  CAS  Google Scholar 

  21. Kreiza G, Berenis D, Banevičius D, et al. High efficiency and extremely low roll-off solution- and vacuum-processed OLEDs based on iso-phthalonitrile blue TADF emitter. Chem Eng J, 2021, 412: 128574

    Article  CAS  Google Scholar 

  22. Ha H, Shim YJ, Lee DH, et al. Highly efficient solution-processed organic light-emitting diodes containing a new cross-linkable hole transport material blended with commercial hole transport materials. ACS Appl Mater Interfaces, 2021, 13: 21954–21963

    Article  CAS  PubMed  Google Scholar 

  23. Yan H, Limbu S, Wang X, et al. Efficient charge carrier injection and balance achieved by low electrochemical do** in solution-processed polymer light-emitting diodes. Adv Funct Mater, 2019, 29: 1904092

    Article  Google Scholar 

  24. Yan H, Cong S, Daboczi M, et al. Ionic density control of conjugated polyelectrolytes via postpolymerization modification to enhance hole-blocking property for highly efficient PLEDs with fast response times. Adv Opt Mater, 2023, 11: 2300988

    Article  CAS  Google Scholar 

  25. Chen Z, Li H, Yuan C, et al. Color revolution: Prospects and challenges of quantum-dot light-emitting diode display technologies. Small Methods, 2024, 8: 2300359

    Article  CAS  Google Scholar 

  26. Chang YF, Yu CH, Yang SC, et al. Great improvement of operationlifetime for all-solution OLEDs with mixed hosts by blade coating. Org Electron, 2017, 42: 75–86

    Article  Google Scholar 

  27. Chen M, **e L, Wei C, et al. High performance inkjet-printed QLEDs with 18.3% EQE: Improving interfacial contact by novel halogen-free binary solvent system. Nano Res, 2021, 14: 4125–4131

    Article  CAS  Google Scholar 

  28. Lim B, Hwang JT, Kim JY, et al. Synthesis of a new cross-linkable perfluorocyclobutane-based hole-transport material. Org Lett, 2006, 8: 4703–4706

    Article  CAS  PubMed  Google Scholar 

  29. Freudenberg J, Jänsch D, Hinkel F, et al. Immobilization strategies for organic semiconducting conjugated polymers. Chem Rev, 2018, 118: 5598–5689

    Article  CAS  PubMed  Google Scholar 

  30. Gather MC, Köhnen A, Falcou A, et al. Solution-processed full-color polymer organic light-emitting diode displays fabricated by direct photolithography. Adv Funct Mater, 2007, 17: 191–200

    Article  CAS  Google Scholar 

  31. Köhnen A, Riegel N, Müller DC, et al. Surface-initiated phase separation-fabrication of two-layer organic light-emitting devices in a single processing step. Adv Mater, 2011, 23: 4301–4305

    Article  PubMed  Google Scholar 

  32. Lee S, Seo MH. Low-temperature cross-linkable small molecules for fully solution-processed OLEDs. Chem Eur J, 2018, 24: 17419–17423

    Article  CAS  PubMed  Google Scholar 

  33. Li Y, Ding J, Day M, et al. Novel stable blue-light-emitting oligofluorene networks immobilized by boronic acid anhydride linkages. Chem Mater, 2003, 15: 4936–4943

    Article  CAS  Google Scholar 

  34. Paul GK, Mwaura J, Argun AA, et al. Cross-linked hyperbranched arylamine polymers as hole-transporting materials for polymer LEDs. Macromolecules, 2006, 39: 7789–7792

    Article  CAS  Google Scholar 

  35. Ma B, Lauterwasser F, Deng L, et al. New thermally cross-linkable polymer and its application as a hole-transporting layer for solution processed multilayer organic light emitting diodes. Chem Mater, 2007, 19: 4827–4832

    Article  CAS  Google Scholar 

  36. Cai Q, Wang S, **ao Y, et al. Application of solution-processed multilayer organic light-emitting diodes based on cross-linkable small molecular hole-transporting materials. Prog Chem, 2018, 30: 1202

    CAS  Google Scholar 

  37. Jeong SH, Jang HJ, Lee JY. High triplet energy crosslinkable hole transport material for blue phosphorescent organic light-emitting diodes. J Industrial Eng Chem, 2019, 78: 324–329

    Article  CAS  Google Scholar 

  38. Dubey DK, Swayamprabha SS, Kumar Yadav RA, et al. A thermally cross-linkable hole-transporting small-molecule for efficient solution-processed organic light emitting diodes. Org Electron, 2019, 73: 94–101

    Article  CAS  Google Scholar 

  39. Tang P, **e L, **ong X, et al. Realizing 22.3% EQE and 7-fold lifetime enhancement in QLEDs via blending polymer TFB and cross-linkable small molecules for a solvent-resistant hole transport layer. ACS Appl Mater Interfaces, 2020, 12: 13087–13095

    Article  CAS  PubMed  Google Scholar 

  40. Zou Y, Liu Y, Ban M, et al. Crosslinked conjugated polymers as hole transport layers in high-performance quantum dot light-emitting diodes. Nanoscale Horiz, 2017, 2: 156–162

    Article  CAS  PubMed  Google Scholar 

  41. Mamada M, Adachi C. Unexpected role of hole and electron blocking interlayers controlling charge carrier injection and transport in TADF based blue organic light-emitting diodes. Appl Phys Lett, 2022, 121: 131103

    Article  CAS  Google Scholar 

  42. Kim Y, Im K, Song H. Charge transport characteristics of molecular electronic junctions studied by transition voltage spectroscopy. Materials, 2022, 15: 774

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Pathak A, Justin Thomas KR, Singh M, et al. Fine-tuning of photophysical and electroluminescence properties of benzothiadiazole-based emitters by methyl substitution. J Org Chem, 2017, 82: 11512–11523

    Article  CAS  PubMed  Google Scholar 

  44. Yan Y, Zhang F, Liu H, et al. Suppressing triplet exciton quenching by regulating the triplet energy of crosslinkable hole transport materials for efficient solution-processed TADF OLEDs. Sci China Mater, 2023, 66: 291–299

    Article  CAS  Google Scholar 

  45. Dey K, Chowdhury SR, Dykstra E, et al. Diazirine-based photo-crosslinkers for defect free fabrication of solution processed organic light-emitting diodes. J Mater Chem C, 2020, 8: 11988–11996

    Article  CAS  Google Scholar 

  46. Zhang Y, Zhou C, Lin L, et al. Gelation of hole transport layer to improve the stability of perovskite solar cells. Nano-Micro Lett, 2023, 15: 175

    Article  CAS  Google Scholar 

  47. Mihailetchi VD, Wildeman J, Blom PWM. Space-charge limited photocurrent. Phys Rev Lett, 2005, 94: 126602

    Article  CAS  PubMed  Google Scholar 

  48. Jiang Z, Yan H, Zhang X, et al. Novel spiro core-based hole transport materials for stable deep-blue OLEDs with LT95 over 420 h. Adv Opt Mater, 2023, 11: 2301014

    Article  CAS  Google Scholar 

  49. Cheng YJ, Liu MS, Zhang Y, et al. Thermally cross-linkable hole-transporting materials on conducting polymer: Synthesis, characterization, and applications for polymer light-emitting devices. Chem Mater, 2008, 20: 413–422

    Article  CAS  Google Scholar 

  50. Yim KH, Doherty WJ, Salaneck WR, et al. Phase-separated thin film structures for efficient polymer blend light-emitting diodes. Nano Lett, 2010, 10: 385–392

    Article  CAS  PubMed  Google Scholar 

  51. Suh M, Bailey J, Kim SW, et al. High-efficiency polymer LEDs with fast response times fabricated via selection of electron-injecting conjugated polyelectrolyte backbone structure. ACS Appl Mater Interfaces, 2015, 7: 26566–26571

    Article  CAS  PubMed  Google Scholar 

  52. Yim KH, Zheng Z, Friend RH, et al. Surface-directed phase separation of conjugated polymer blends for efficient light-emitting diodes. Adv Funct Mater, 2008, 18: 2897–2904

    Article  CAS  Google Scholar 

  53. Woo JY, Park MH, Jeong SH, et al. Advances in solution-processed OLEDs and their prospects for use in displays. Adv Mater, 2023, 35: 2370314

    Article  Google Scholar 

  54. Han SH, Jeong JH, Yoo JW, et al. Ideal blue thermally activated delayed fluorescence emission assisted by a thermally activated delayed fluorescence assistant dopant through a fast reverse intersystem crossing mediated cascade energy transfer process. J Mater Chem C, 2019, 7: 3082–3089

    Article  CAS  Google Scholar 

  55. Sun J, Ahn H, Kang S, et al. Exceptionally stable blue phosphorescent organic light-emitting diodes. Nat Photon, 2022, 16: 212–218

    Article  CAS  Google Scholar 

  56. Yao J, Dong SC, Tam BST, et al. Lifetime enhancement and degradation study of blue OLEDs using deuterated materials. ACS Appl Mater Interfaces, 2023, 15: 7255–7262

    Article  CAS  PubMed  Google Scholar 

  57. Yadav RAK, Dubey DK, Chen SZ, et al. Role of molecular orbital energy levels in OLED performance. Sci Rep, 2020, 10: 9915

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  58. Bangsund JS, Van Sambeek JR, Concannon NM, et al. Sub-turn-on exciton quenching due to molecular orientation and polarization in organic light-emitting devices. Sci Adv, 2020, 6: eabb2659

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Song SH, Yoo JI, Kim HB, et al. Manipulation of hole and exciton distributions in organic light-emitting diodes with dual emission layers. Electron Mater Lett, 2024, 20: 232–242

    Article  CAS  Google Scholar 

  60. de Moraes IR, Scholz S, Lüssem B, et al. Role of oxygen-bonds in the degradation process of phosphorescent organic light emitting diodes. Appl Phys Lett, 2011, 99: 053302

    Article  Google Scholar 

  61. **a SC, Kwong RC, Adamovich VI, et al. Oled device operational lifetime: Insights and challenges. In: 2007 IEEE International Reliability Physics Symposium Proceedings. Phoenix: IEEE, 2007. 253–257

    Google Scholar 

  62. Song W, Lee JY. Degradation mechanism and lifetime improvement strategy for blue phosphorescent organic light-emitting diodes. Adv Opt Mater, 2017, 5: 1600901

    Article  Google Scholar 

  63. Giebink NC, D’Andrade BW, Weaver MS, et al. Direct evidence for degradation of polaron excited states in organic light emitting diodes. J Appl Phys, 2009, 105: 124514

    Article  Google Scholar 

  64. Xu QL, Liang X, Zhang S, et al. Efficient OLEDs with low efficiency roll-off using iridium complexes possessing good electron mobility. J Mater Chem C, 2015, 3: 3694–3701

    Article  CAS  Google Scholar 

  65. Murawski C, Leo K, Gather MC. Efficiency roll-off in organic light-emitting diodes. Adv Mater, 2013, 25: 6801–6827

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Natural Science Foundation of China (22275003), Shenzhen Fundamental Research Program (JCYJ20200109140425347), the Development and Reform Commission of Shenzhen Municipality (XMHT20200106002), the Key-Area Research and Development Program of Guangdong Province (2019B010924003), and Guangdong Basic and Applied Basic Research Foundation (2020B1515120030). Additional support was provided by Guangdong Key Laboratory of Flexible Optoelectronic Materials and Devices and Guangdong International Science and Technology Cooperation Base of Optoelectronic Materials and Device Technology.

Author information

Authors and Affiliations

  1. School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen, 518055, China

    **nkang Zhang  (张鑫康), Hao Yan  (严浩), **aopeng Zhang  (张小鹏) & Hong Meng  (孟鸿)

Authors
  1. **nkang Zhang  (张鑫康)
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Hao Yan  (严浩)
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. **aopeng Zhang  (张小鹏)
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Hong Meng  (孟鸿)
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

Author contributions Zhang X conducted the experiments, analyzed the data, and wrote the original draft of the manuscript. Yan H was integral to the design of the experiments, participated in data analysis, and revised the manuscript. Zhang X was responsible for the theoretical calculations and their interpretation. Meng H acquired funding, managed the project, and contributed to the revision of the paper.

Corresponding author

Correspondence to Hong Meng  (孟鸿).

Ethics declarations

Conflict of interest The authors declare that they have no conflict of interest.

Additional information

Supplementary information Experimental details and supporting data are available in the online version of the paper.

**nkang Zhang graduated from Nan**g University with a BS degree in 2019. Then he entered Peking University Shenzhen Graduate School as a PhD student under the supervision of Prof. Hong Meng. His research interest is the synthesis of thermally cross-linkable HTMs used in solution-processed light emitting devices (OLEDs and QLEDs) and fused-ring triarylamine-based emitters with ultra-violet narrow emission spectra.

Hao Yan joined Prof. Hong Meng’s group as a post-doc fellow in November 2021. He completed his PhD degree in organic semiconductor physics in 2021 under the supervision of Prof Ji-Seon Kim at the Imperial College London, UK. His main research is focused on charge carrier injection and transport properties, and degradation mechanisms of solution-processed organic optoelectronic devices, such as OLEDs (polymers, or TADFs), OPVs and OPDs.

**aopeng Zhang graduated from Jilin University with a BS degree in 2022. He is a PhD candidate at Peking University Shenzhen Graduate School under the supervision of Prof. Hong Meng. His research focuses on material synthesis, device fabrication, and theoretical computational simulations. He is currently primarily engaged in the research in the field of photodetectors.

Hong Meng received his PhD degree from the University of California Los Angeles (UCLA) in 2002. His career experiences including working at the Institute of Materials Science and Engineering (IMRE), Singapore, Lucent Technologies Bell Labs, and DuPont Experimental Station. In 2014, he joined the School of Advanced Materials, Peking University Shenzhen Graduate School. His research utilizes the basic principles in chemistry, physics and material sciences to enable novel applications and development of organic optoelectronic devices.

Supporting Information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhang, X., Yan, H., Zhang, X. et al. Thermally cross-linkable hole-transport materials enable solution-processed blue OLED with LT95 over 150 h. Sci. China Mater. (2024). https://doi.org/10.1007/s40843-024-2888-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s40843-024-2888-2

Keywords

Search

Navigation